This invention relates to an ozone generator, and more particularly, to a deodorizing and sterilizing apparatus including the ozone generator, the electrode of which has the photo-catalytic function, the high corrosion resistance against ozone and the high mechanical workability.
This invention also relates to a photo-catalytic material, and more particularly, a photo-catalytic electrode used in the ozone generator and a method for manufacturing the photo-catalytic material.
The conventional ion and/or ozone generator of a compact and easy-to-handle type is not guaranteed for generating ozone. The electrode of such an ozone generator is easily oxidized due to a strong oxidative property of ozone and can not have a long-durability by the corrosion due to ozone. Accordingly, the conventional ions and ozone generators have only an insufficient deodorizing and sterilizing effect.
Therefore, it is an object of the invention to provide a photo-catalytic electrode material with a high corrosional resistance against ozone.
It is another object of the invention to provide a deodorizing and sterilizing device of a compact, easy-to-handle and less expensive type which makes the electrode emit ultra-violet rays to activate the photo-catalytic function of the electrode.
An ion/ozone generator according to the invention includes a cylindrical electrode and a needle-like electrode, which are made of titanium oxide, the tip of which is positioned on substantially the center axis of the cylindrical electrode and emits ultra-violet radiation. The ion/ozone generator has an air flow along the inner surface of the cylindrical electrode.
In another aspect of the invention, as a cylindrical electrode is made of a photo-catalytic material and a tip of a needle-like electrode emits ultra-violet rays, the ion/ozone generator of the invention has a photo-catalytic function.
In yet another aspect of the invention, the tip of the needle-like electrode is positioned substantially on the center axis of the cylindrical electrode and with an interval from the end of the cylindrical electrode.
The electrode used in the ion/ozone generator of the invention is formed of the photo-catalytic material made of the sintered and rolled titanium oxide. In another aspect, the electrode is formed of the plate-like material made of the sintered and rolled titanium oxide powder to which a slight amount of iron, carbon, nickel and/or zirconium are added for improving the mechanical workability of the sintered titanium oxide.
In still another aspect of the invention, a method for producing a photo-catalytic material used for electrodes is provided. In this method, powder of titanium oxide, in which a slight amount of iron, carbon, copper, nickel, and/or zirconium is added in order to improve the property of a sintered metal, is heated and melted at a temperature lower than the melting point in the atmosphere. Then, a plate-like ingot is formed. The ingot is rolled out repeatedly in order to form a plate with a predetermined thickness, which is easy to machine, bend, and cut. Finally, the ingot plate is cut into multiple pieces having predetermined sizes, which are then shaped into cylindrical electrodes or needle-like electrodes.
If a full-wave rectified high-frequency and high-voltage direct current is applied between a needle-like electrode and a cylindrical electrode, the needle-like electrode discharges and produces a beam containing ultra-violet rays. In accordance with the invention, this phenomenon was recognized in the extent of the so-called silent discharge. The ozone and ions flow along the inner surface of the cylindrical electrode. The ultra-violet rays emitted from the tip of the needle electrode activate the photo-catalytic function of the cylindrical electrode. Since the cylindrical electrode is made of a material containing titanium oxide, it has a photo-catalytic function, which is stimulated by ultra-violet rays. An air current containing the stream of ions and ozone flows along the inner surface of the cylindrical electrode, while it is being subjected to both the photo-catalytic action due to the ultra-violet rays and oxidation due to ozone. Consequently, odor components contained in the air current are rapidly decomposed and deodorized by the oxidation ability of ozone. At the same time, bacteria contained in the air current are also sterilized.